What's new here is the autoplay feature. It's sure to be controversial because it does not offer users a choice, per Ad Age:

... the visual component of the Facebook video ads will start playing automatically -- a dynamic known as "autoplay" -- according to two of the executives. Facebook is still debating whether to have the audio component of the ads activated automatically as well, one of these people said.

On the desktop version of Facebook, the video ads are expected to grab a user's attention by expanding out of the news feed into webpage real estate in both the left and right columns -- or rails -- of the screen. Facebook is also working on a way to ensure that the video ads stand out on the mobile apps as well, though it is unclear how exactly the company will accomplish this.

Video ads are already being served to users who have liked a company's page. The new ads, Ad Age says, could be targeted at anyone the advertiser chooses.

Facebook is planning on introducing the feature with another twist that will roil the agency business: The ad units will only be 15 seconds long, as opposed to the standard 30. This will force agencies to trim their most-prized content — TV commercials — or make new Facebook content from scratch.